Figure 8: The Devices and Interfaces item
If MAX recognizes the USB-6009, the device appears under
NI-DAQmx Devices
.
Assuming that MAX recognizes the device, you can now run a self-test of it by selecting
Self-Test
in
the menu.
Hopefully the self-test passes without errors. Then, you should test the individual channels of the USB-
6009 to check that the input signals are detected correctly by the USB-6009, and that the output signals
generated by the USB-6009 have correct values. This I/O can be tested in several ways, depending on
which channels you actually want to test. Here, let us test analog output channel 0 (AO0) and the
analog input channel 0 (AI0) to see if they work correctly. We will perform a very simple test, which is
sufficient if we are to check that both AO0 and AI0 work correctly. The test procedure, which is
denoted
loopback
, is to connect the AI0 channel to the AO0 channel. Then we generate some legal
voltage at AO0. If AI0 detects the same voltage, we know that both AO0 and AI0 works. (We may then
repeat this procedure for other channels.) If for some reason AI0 detects some other voltage than the
value we set for AO0, then there is an error in either the AI0 channel or in the the AO0 channel, and
further investigations are necessary.
To prepare for the loopback test, we wire together AI0 and AO0. To see the terminals of the USB-6009,
select
Device Pinouts
in the menu shown in Figure 8. The terminals or pins are shown in the NI-
DAQmx Device Terminals window, see Figure 9.
Page 8 of 21
TechTeach: A quick guide to National Instruments USB-6009 and USB-6008 multifuncti ...
2/14/2009
http://techteach.no/tekdok/usb6009/
